We’re in the thick of winter, which means your plants might be looking a little worse for wear. In fact, chances are those yellowing, brown, or wilting leaves you’re noticing are early signs of plant stress. Plant stress describes a set of non-ideal growth conditions within which your plants are forced to survive. Though not immediately disastrous, prolonged plant stress can cause a host of different issues for your plants, including growth deficiencies, permanent damage, and death. Fear not, however: this guide will demystify common causes of winter plant stress and help you decode common plant stress signs so you’ll know how best to help your houseplants.
Causes For Plant Stress in Winter
The first and perhaps most obvious cause of winter plant stress is a lack of sunlight. Shortened days mean less access to sunlight, which in turn means your houseplants can’t produce the same amount of energy through photosynthesis as they normally would.
Because they’re not producing as much energy, plants don’t need as much water during the winter months. Unfortunately, many plant parents operate on the same watering schedule year-round, which leads to our second cause of winter plant stress: overwatering. Because soil doesn’t dry out as quickly in the winter as in the active growing season, overwatering can kill your plants’ roots through a prolonged lack of oxygen. Overly-moist soil is also a prime breeding ground for pests like mold and fungus gnats, further stressing out your plants.
On the opposite end of the humidity spectrum, another common plant stress trigger is dry air from our furnaces, fireplaces, and heaters. Hot, dry air pulls moisture out of your plants’ cells, placing them under tremendous stress. Tropical plants are especially susceptible to a lack of humidity, as most need at least 50% humidity in their environment to be comfortable. Anything less will stress them out considerably.
The final common cause of winter plant stress we’ll go over is cold drafts. Most common indoor houseplants don’t do well with rapid temperature changes, and they’re especially not fond of cold air drafts. This means that your plant’s favorite spot in your window sill could be seriously stressing them out during the winter months!
Common Signs of Houseplant Stress
As you can see, there are many seemingly contradictory reasons why your plants might be stressed out: they’re too hot and too cold, both overwatered and dried out. To help you better decode what your plants are trying to tell you, here are a few common plant stress signs, their causes, and what you can do to alleviate them:
Yellowing Leaves
Yellowing leaves can be a sign of both overwatering and underwatering. If your plant is thirsty, its leaves will turn yellow and drop to conserve water. If your plant’s getting too much water, the roots can suffocate and rot, again causing yellowing leaves. To determine which watering imbalance is affecting your plant, simply check the soil: is it soaked through or bone dry? Another good telltale sign is the leaves themselves; underwatered leaves will be dry and crunchy, while overwatered leaves will be wet and mushy.
Correcting yellowing leaves will depend on the cause. If your plant’s underwatered, a simple top-up should do the trick. If it’s been overwatered, try repotting it in fresh soil. Plants with fully-rotten roots are a lost cause, however, so make sure you catch it before it’s too late.
While over- and underwatering are the two most common causes of yellowing leaves, a ton of other factors can also cause your plant’s leaves to turn, including exposure to cold drafts, lack of sunlight, or transplant shock after being repotted. If moisture levels don’t seem to be the cause of your plant’s yellowing leaves, consider troubleshooting for some of these other potential causes.
Brown Leaves
If you’re noticing your plant’s lower leaves are turning brown or yellow, it might be a sign of lack of sunlight. This is typically the case when the leaf discoloration occurs primarily on the side of the plant that faces away from the nearest light source. To correct this issue, move your plant to a brightly lit south-facing window and rotate it regularly to ensure all sides receive adequate sunlight. Alternatively, you may also want to consider placing it under a grow light.
If only the tips of your plant’s leaves are brown, it’s telling you that it needs more humidity. If this is the case, mist the plant more often or run a humidifier nearby.
Leaf and Flower Drop
If your plant is dropping its flowers and leaves, it could be another sign that it’s suffering from a lack of sunlight. For instance, leaf drop frequently happens when plants are brought inside for the winter after spending all summer basking in the plentiful outdoor rays. If this is the case, move your plant in front of a bright south-facing window or place it underneath some grow lights.
Moving your plants can also shock them into dropping their flowers and leaves. If you suspect this might be the cause, give your plant time to settle into its new environment before troubleshooting further.
Finally, plants are creatures of habit, so repotting a plant can sometimes bring on transplant shock and inspire the dropping of leaves. To prevent transplant shock, thoroughly water your plant after repotting it, and be careful not to disturb its root system too much.
It can be scary to see your plants withering over the winter. After all, no one enjoys an unhappy houseplant. However, the tips we’ve outlined here will help you better recognize the common causes, signs, and treatments for winter plant stress so you can keep your plant babies happy all season long! If you would still like some help troubleshooting possible signs of plant stress, stop by and chat with us at Plant Perfect in Bismarck, ND. We’re happy to help as best we can and point you in the right direction!